Ever needed to check really quick how many CPUs your *nix machine is running? Maybe you're logged into a remote server, or maybe you just forgot. In any case, I keep finding myself in a such situations and have had to look this up more than once.
Here's a couple ways to go about it. On Linux boxes you can run:
> grep -c processor /proc/cpuinfo
=> 4
Or opt for the less verbose:
> nproc
=> 4
On MacOS:
> sysctl -n hw.physicalcpu
=> 8